Bobbin crafting and thread feeding device for circular knitting machines

ABSTRACT

For use in a knitting machine having at least one thread brake for every thread pulled off a bobbin means and non-positive thread feeder means, a bobbin grating having housed therein a thread feeder device associated with every non-positive thread, said thread feeder device transporting the thread with at least the same speed as the associated thread feeder means on said knitting machine.

United States Patent 11 1 Schmidt et al.

[ BOBBIN CRAFTING AND THREAD FEEDING DEVICE FOR CIRCULAR KNITTING MACHINES [75] Inventors: Gerhard Schmidt; Werner Jansch,

both of Stuttgart-Vaihingen, Germany [73] Assigriee: Firma Franz Morat GmbH,

Stuttgart-Vaihingen, West Germany 22 Filed: Mar. 12,1971

21 Appl.No.: 123,658

[30] Foreign Application Priority Data Mar. 17, 1970 Germany P 20 12 617.4

[52] US. Cl. 66/125 R, 66/132 R [51] Int. Cl D04b 15/48 [58] Field of Search 66/125 R, 125 A, 66/132 R, 132 T [56] References Cited UNITED STATES PATENTS 3,093,330 6/1963 Schmidt 66/125 R UX 3,461,691 8/1969 Ballard 1. 66/125 R 1 1 Oct. 2, 1973 3,490,710 1/1970 Mulhausler 66/132 RX 3,542,309 11/1970 Willis et al. .1 3,589,146 6/1971 Schmidt 66/125 R FORElGN PATENTS OR APPLlCATlONS 789,822 1/1958 Great Britain 66/132 R 872,158 7/1961 Great Britain 66/132 R OTHER PUBLICATIONS Knitted Outerwear Times, March 31, 1969, Vol. 38, No. 13, pps. 43, 44, 45.

Primary Examiner-R0bert R. Mackey Attorney-John Lezdcy [57] ABSTRACT For use in a knitting machine having at least one thread brake for every thread pulled off a bobbin means and non-positive thread feeder means, a bobbin grating having housed therein a thread feeder device associated with every non-positive thread, said thread feeder device transporting the thread with at least the same speed as the associated thread feeder means on said knitting machine.

1 Claim, 2 Drawing Figures PATENTED 2|973 3.762.185

SHEET 1 UF 2 FIG. 7

INVIiN'I'ORS GEKHARD S HMIDT *UERNFR 5mm- BYQ'MQM AT ToM EY PATENTEDUIIT 2 sum 2 OF 2 FIG. 2

IN VENTOR$'- GERHRRD .5CHMID7- \JERNER UANSCH BOBBIN CRAFTING AND THREAD FEEDING DEVICE FOR CIRCULAR KNITTING MACHINES This invention relates to knitting machines. More particularly, this invention relates to spool or bobbin gratings or frames for knitting machines having thread feeder means and at least one thread brake for eachof the threads pulled off a bobbin or a pair of bobbins.

In prior art combinations of bobbin gratings and knit ting machine, as disclosed for example, in the French Pat. No. 2,014,781, there is-the disadvantage that the threads must travel differently long distances from the bobbins to the knitting points. As a result of this and because of the stretch which prevails in every thread, there is obtained differing thread tensions at all knitting points so that there can be no uniform stitch formation. The differences in the thread tensions are further increased by the differing friction conditions at the individual thread eyes or thread guidance or diversion points in the bobbin grating.

It is therefore an object of this invention to avoid the prior art disadvantages and to create an installation by means of which one can guarantee uniform thread tension at all knitting points even though all threads must travel different long distances up to the knitting points.

In accordance with this invention there is provided an additional thread feeder means housed in the bobbin grating that is associated with every thread and this means transports the thread with at least the same speed as the corresponding thread feeder device on the knitting machine.

The invention offers the considerable advantage that the thread tension on the way between the bobbin grating and the knitting machine is almost reduced to zero tension or there is attained a situation in which the thread will sag in this area so that a thread reserve is formed. By means of this invention the thread tension is essentially the same at all inlet or feed-in points leading to the knitting machinewhen the threads have to cover different long distances so that one can adjust the thread tensions at all knitting points by means of the thread brakes and feeder means arranged on the knitting machine.

According to another feature of this invention, the threads are transported from the thread feeder devices of the bobbin grating frame and the knitting machine with slippage. Preferably, the feeder devices are used as shown in US. Pat. No. 3,093,330, according to which the feeder element is a cylinder that comes in the form of a rotor of an electric motor.

If, from time to time, the thread consumption at the knitting point is greater than normal, then the feeder devices in the bobbin grating will preferably transport faster than the feeder devices on the knitting machine so that the threads can be drawn off out of a tensionfree or quiet zone by the feeder devices of the knitting machine. The thread reserve which is formed in the area between the bobbin grating and the knitting machine is best made so large that any desired pattern and/or binding can be made.

When the invention is used on a circular knitting machine it is preferable to provide two bobbin grating segments arranged diametrally with respect to the circular knitting machine. These segments, in each case, carry half of the bobbins or bobbin pairs required for all feeder devices, although one can also provide more than two bobbin grating segments. In every case, however, it is advantageous to arrange the bobbin gratings at such a distance from the circumference of the knitting machine and at such a height that the operator can work unhindered among the thread-screen formed between the bobbin grating and the knitting machine.

For a better understanding of the present invention reference should be made to the accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS:

FIG. 1 is a side view ofa bobbin grating for a circular knitting machine illustrated up to the center axis in accordance with this invention.

- FIG. 2 is a schematic top view upon two bobbin grating segments which are arranged to the right and to the left of a 24-system circular knitting machine in accordance with this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings in detail there can be seen in FIG. 1 four rows of bobbins I, la, 2, 20 arranged under each other in a bobbin frame or grating 15. In bobbins I, la, 2, 2a, the end of the thread 3 which constitutes the wound body of bobbin 1 or 2 is tiedtogether with the beginning of the wound body of bobbin 1a or 2a so that, after bobbin 1 or 2 has run out, a new bobbin can be put on and the beginning of the thread of that bobbin is tied together with the end of the thread of bobbin la or 2a, etc. This guarantees uninterrupted thread supply to the knitting points.

Threads 3 run through eyes 4, 4a; thread brakes 5,

511; thread guards 6, 6a; thread eyes 7, 711; via thread feeder devices 8, 8a; through thread eyes 9, 9a; and thread guide or diversion points 10.

From the thread guide points 10, the threads are guided through thread eyes 11, which are attached to the circular knitting machine 20, and from these eyes they are guided to the thread feeder devices 12 of the circular knitting machine 20 and via thread brakes 13 to the knitting points 14. The thread brakes 13 can also be arranged in front of the thread feeder device 12.

FIG. 2 is a schematic top view of two bobbin frame segments 15 and which are arranged to the left and to the right at the proper distance from the circular knitting machine 20. It is, for example, assumed .that

' the circular knitting machine 20 has 24 systems and 24 thread feeder devices 12. The bobbin gratings l5 and 15a each have 12 bobbins I and 2, respectively, bobbin pairs 1, la and 2, 20, whereby, according to FIG. 2, each grating consists of six bobbin pairs.

The two bobbin gratings 15, 15a conduct the threads 3 in each case to the 12 thread feeder devices 12 of the circular knitting machine which face them. All thread feeder devides 8, 8a, and 12 may be non-positive thread feeders as feeder rollers in the example described and the thread is laid around them fully or partially and these rollers rotate at a considerably higher rpm than the thread speed, that is, they make sure that the thread will be transported with slippage.

When the thread requirement at the knitting points 14 is considerably greater than during the normal knitting process, for example, during relief design, a thread reserve is created by virtue of the fact that the circumferential speed of the feeder rollers 8, 8a in the bobbin grating is selected greater than thatof the feeder rollers of the circular knitting machine 20.

The different long distances, which the threads must cover, can be clearly seen in FIG. 2. The resultant differing thread tensions at the knitting points are avoided, according to to this invention, by virtue of the fact that there is provided for each knitting point two feeder devices, more particularly, one at the knitting machine and at the bobbin grating.

The foregoing is considered as illustrative only of the principles of the invention and a wide variety of embodiments may be devised without departing from the spirit and scope thereof.

What is claimed is:

1. In combination with a circular knitting machine with a plurality of knitting positions, having at least one thread brake and a first non-positive thread feeder means for every thread pulled off a bobbin means and fed to a knitting point; a bobbin grating spaced from said knitting machine comprising a seond non-positive thread feeder device associated with every thread, said second feeder device trasnporting the thread with at least the same speed as the associated first thread feeder means on said knitting machine; a thread brake for every thread in said bobbin grating the thread brakes in said bobbin being disposed in front of said second feeder devices; said bobbin grating having two segments arranged on two sides diametrically opposite said circular knitting machine, and with each of said segments carrying half of all bobbins; whereby the thread tension on the way between the bobbin grating and the knitting machine is substantially reduced and the thread tension is essentially the same at all feed-in points leading to the knitting machine. 

1. In combination with a circular knitting machine with a plurality of knitting positions, having at least one thread brake and a first non-positive thread feeder means for every thread pulled off a bobbin means and fed to a knitting point; a bobbin grating spaced from said knitting machine comprising a seond nonpositive thread feeder device associated with every thread, said second feeder device trasnporting the thread with at least the same speed as the associated first thread feeder means on said knitting machine; a thread brake for every thread in said bobbin grating the thread brakes in said bobbin being disposed in front of said second feeder devices; said bobbin grating having two segments arranged on two sides diametrically opposite said circular knitting machine, and with each of said segments carrying half of all bobbins; whereby the thread tension on the way between the bobbin grating and the knitting machine is substantially reduced and the thread tension is essentially the same at all feed-in points leading to the knitting machine. 